Mercedes-Benz GLA MOT pass rate & common failures

At a glance

Pass rate, adjusted for age and mileage

The GLA is 10.0 percentage points above the national pass rate once age and mileage are accounted for, which is well above average. The unadjusted figure is 83.3%; the difference is what the age and mileage of this model’s fleet was hiding.

DVSA recorded wording

Most common failure items

Share of failed Mercedes-Benz GLA tests in which each item was recorded. One failed test often lists several items, so these do not sum to 100%.

1. 1.Tyre tread depth not in accordance with the requirements17.4%

   2,255 occurrencesTyre worn close to the legal limit explained

2. 2.A spring or spring component fractured or seriously weakened14.6%

   1,891 occurrencesRoad spring broken or fractured explained

3. 3.A transmission shaft constant velocity joint boot missing or no longer prevents the ingress of dirt etc14.0%

   1,816 occurrencesDriveshaft CV joint gaiter split or missing explained

4. 4.A suspension joint dust cover missing or no longer prevents the ingress of dirt etc12.9%

   1,679 occurrencesSuspension joint dust cover missing or split explained

5. 5.A tyre seriously damaged12.8%

   1,663 occurrencesTyre damaged or deteriorated explained

6. 6.A brake lining or pad worn below 1.5mm12.4%

   1,605 occurrencesBrake drum or shoe worn or contaminated explained

7. 7.Wiper blade missing or obviously not clearing the windscreen6.1%

   791 occurrencesWiper or washer not working properly explained

8. 8.A suspension joint dust cover missing or no longer prevents the ingress of dirt etc5.8%

   760 occurrencesSuspension joint dust cover missing or split explained

9. 9.A tyre cords visible or damaged5.7%

   738 occurrencesTyre ply or cord exposed, or the casing separating explained

10. 10.Engine MIL illuminated indicating a malfunction5.0%

    655 occurrencesEngine management light on, or not working explained

Warnings without a failure

Most common advisories

Share of all Mercedes-Benz GLA tests carrying each advisory. The denominator differs from the failure list above because an advisory can be issued on a car that passed.

1. 1.Tyre tread depth not in accordance with the requirements21.7%

   19,968 testsTyre worn close to the legal limit explained

2. 2.A tyre seriously damaged14.6%

   13,413 testsTyre damaged or deteriorated explained

3. 3.A brake lining or pad worn below 1.5mm10.6%

   9,704 testsBrake drum or shoe worn or contaminated explained

4. 4.Brake disc or drum excessively weakened, insecure or fractured8.9%

   8,213 testsBrake disc worn, pitted or scored explained

5. 5.Brake disc or drum significantly and obviously worn5.4%

   4,986 testsBrake disc worn, pitted or scored explained

6. 6.Tyre tread depth not in accordance with the requirements3.2%

   2,955 testsTyre worn close to the legal limit explained

7. 7.Child Seat fitted not allowing full inspection of adult belt3.1%

   2,823 tests

8. 8.Nail in tyre2.6%

   2,346 tests

How wear changes the picture

Pass rate by vehicle age

Bands holding too few tests to be meaningful are omitted rather than shown as a rate.

What gets tested

The GLA fleet

Average mileage recorded at test

52,958

Across examples of every age, so this is a description of the fleet rather than an annual figure.

Fuel mix of tested cars

Petrol49.3%

Diesel47.4%

Hybrid3.3%

Compare within the range

Other Mercedes-Benz models

• Mercedes-Benz A-Class — 73.3% adjusted
• Mercedes-Benz C-Class — 77.0% adjusted
• Mercedes-Benz E-Class — 78.5% adjusted
• Mercedes-Benz Vito — 71.0% adjusted
• Mercedes-Benz GLC — 85.9% adjusted
• Mercedes-Benz CLA — 78.6% adjusted
• All Mercedes-Benz models →

Similar test volumes

Compare against other makes

• BMW X5 — 81.8% adjusted, ranked 41
• Renault Megane — 63.3% adjusted, ranked 238
• Mazda MX-5 — 77.2% adjusted, ranked 85
• Jaguar XF — 77.9% adjusted, ranked 74

Common questions

Is the Mercedes-Benz GLA reliable?

On MOT evidence the Mercedes-Benz GLA is well above average. It passes 82.3% of tests once age and mileage are accounted for, against a national average of 72.3%. That figure covers 62% of the national age and mileage range, which is enough to quote but not to rank. This measures how often the car meets the MOT standard, not how often it breaks down or what a repair costs.

What is the most common MOT failure on a Mercedes-Benz GLA?

The item recorded most often is "Tyre tread depth not in accordance with the requirements", which appears in 17.4% of failed Mercedes-Benz GLA tests. Because one failed test can list several items, these shares do not add up to 100%.

What do testers most often warn about on a Mercedes-Benz GLA?

The most common advisory is "Tyre tread depth not in accordance with the requirements", noted on 21.7% of all Mercedes-Benz GLA tests. An advisory is not a failure: it flags something that will likely need attention before the next test.

What mileage does a Mercedes-Benz GLA usually have at its MOT?

The average odometer reading recorded at test is 52,958 miles. This is the mileage across all tested examples of every age, not an annual figure, so treat it as a description of the fleet rather than a target for one car.

Does a Mercedes-Benz GLA get harder to pass as it ages?

Yes. At 3 to 5 years old, 90.8% of Mercedes-Benz GLA tests pass. By 9 to 11 years, that falls to 77.1%. Nearly every model follows this pattern, which is why comparing raw pass rates between models is misleading unless age is accounted for.

Are most Mercedes-Benz GLA models petrol or diesel?

Of the Mercedes-Benz GLA cars tested, 49% are petrol, 47% are diesel, 3% are hybrid. Fuel type affects which items tend to fail, particularly emissions and exhaust components.

How this was worked out

Method and limits

Figures come from the DVSA anonymised MOT testing dataset, published under the Open Government Licence. Only class 4 initial tests are counted: retests are excluded so a car appears once, and abandoned tests are excluded entirely. The adjusted rate is directly standardised across twenty-five age and mileage bands and reweighted onto the national distribution, so this model is compared against cars that have lived a similar life rather than against a younger or lighter-used fleet.

An MOT measures whether a car met a legal standard on the day. It is not a breakdown record, a service history or a running-cost estimate, and a pass rate is a property of a fleet rather than a prediction about one car.

Further reading

Make sense of the numbers

• How to judge reliability from evidence rather than reputation
• What counts as high or low mileage for a car’s age
• The most common MOT failures and how to avoid them
• What to check before buying a used Mercedes-Benz